With the popularity of mobile terminals, such as smart phones, and the improvement of metal housing manufacturing process, a metal housing is employed in more and more mobile phones and makes the smart phone more advanced due to its high heat dissipation capacity, high mechanic strength (enabling the metal housing to be thinned so as to meet the need of consumers for ultra-thin equipment), unique metallic luster and fashion appearance. As the metal housing may produce electrostatic shielding effect which affects the emission and reception of radio frequency, the metal housing is generally designed in a three-section manner, in which an intermediate piece and two end pieces of the metal housing is spaced apart by providing a groove therebetween, and connected into an integral housing by a plastic injected into the groove and molded therein. In this way, the end piece of the metal housing is connected to the PCB plate of the antenna via a conductor, such that the end piece possesses a signal radiation function and becomes a part of the antenna.
However, in order to improve the integrity of the metal housing, a width of the end piece of the metal housing narrows down. In such a case, the plastic is easily detached from the end piece when the phone falls or is under external shocks, resulting in damage of the metal housing.